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Speaker Causing Advent 300 Receiver to Blow Fuse???

Grid

Grid

Active Member
I connected a single speaker rated at 36W max to one channel of an Advent 300 receiver. As soon as the volume was up to 11 O'Clock, clipping started and the receiver blew a fuse. I replaced the fuse and hooked the Advent 300 to Advent speakers (OLA) and there were no problems even up to 1 O'Clock. What baffles me is, I hooked up the 36W speaker to a Sansui AU-7900, which is four times the watts of the Advent 300, and at 11 O'Clock it played that 36W speaker with no problems (as a precaution, I only did this for maybe half minute).

Why is the Advent 300 (15 wps) blowing a fuse only when connected to that 36W speaker?
 
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Grid said:
I connected a single speaker rated at 36W max to one channel of an Advent 300 receiver. As soon as the volume was up to 11 O'Clock, clipping started and the receiver blew a fuse. I replaced the fuse and hooked the Advent 300 to Advent speakers (OLA) and there were no problems even up to 1 O'Clock. What baffles me is, I hooked up the 36W speaker to a Sansui AU-7900, which is four times the watts of the Advent 300, and at 11 O'Clock it played that 36W speaker with no problems (as a precaution, I only did this for maybe half minute).

Why is the Advent 300 (15 wps) blowing a fuse only when connected to that 36W speaker?
Click to expand...

I would guess it has to do with the impedance of the speaker. There's probably a point in the frequency range where that 36w speaker drops in impedance pretty low. The sansui is a more robust unit and is able the handle the impedance drop.

What is the 36 watt speaker?
 
Wattage ratings do not really matter when it comes to speakers with a low powered receiver like the Advent 300. What does matter is impedance! If the speaker is less than 4ohms impedance, STOP! DO NOT USE IT! Advent 300 receivers are most happy with an 8ohm load (speaker) attached to them, and are the safest bet to use so as not to blow fuses and incur damage. 4-ohm speakers like the Smaller Advent can be used, but only with ONE PAIR and NO MORE THAN THAT. Sounds like you are trying to use a 2ohm car speaker of some type to try and test things......not a good idea as you have found out.
 
waggs098 said:
I would guess it has to do with the impedance of the speaker. There's probably a point in the frequency range where that 36w speaker drops in impedance pretty low. The sansui is a more robust unit and is able the handle the impedance drop.

What is the 36 watt speaker?
Click to expand...
Agree; and yeah what is it.
 
stereoguy70 said:
Wattage ratings do not really matter when it comes to speakers with a low powered receiver like the Advent 300. What does matter is impedance! If the speaker is less than 4ohms impedance, STOP! DO NOT USE IT! Advent 300 receivers are most happy with an 8ohm load (speaker) attached to them, and are the safest bet to use so as not to blow fuses and incur damage. 4-ohm speakers like the Smaller Advent can be used, but only with ONE PAIR and NO MORE THAN THAT. Sounds like you are trying to use a 2ohm car speaker of some type to try and test things......not a good idea as you have found out.
Click to expand...
Yes, I guess I should've been specific. It's an 8 ohm 3-way Utah A-100. These (Moderators: this eBay listing is not longer active): https://www.ebay.com/itm/Vintage-Ut...nsion-RARE-HORN-LOADED-MIDRANGE/253431201225?
 
waggs098 said:
I would guess it has to do with the impedance of the speaker. There's probably a point in the frequency range where that 36w speaker drops in impedance pretty low. The sansui is a more robust unit and is able the handle the impedance drop.

What is the 36 watt speaker?
Click to expand...
I hadn't thought of that. In fact, that makes great sense, because as I increased bass, the clipping would start. This is a 3-way speaker system, so I guess when increasing the bass, the impedance of the speaker is changing so as to produce the more bass? (Moderators, please note this is an expired listing): https://www.ebay.com/itm/Vintage-Ut...nsion-RARE-HORN-LOADED-MIDRANGE/253431201225?
 
Hello again, everybody. Another clue I failed to mention. This started happening after I recapped the speaker. Before I recapped, I could really crank the speaker using the Advent 300 ("crank" for testing purposes). And the caps were so bad, no juice was getting to the tweeter; I was getting horn and driver only.
 
Grid said:
Hello again, everybody. Another clue I failed to mention. This started happening after I recapped the speaker. Before I recapped, I could really crank the speaker using the Advent 300 ("crank" for testing purposes). And the caps were so bad, no juice was getting to the tweeter; I was getting horn and driver only.
Click to expand...

I would open the speaker up and check to make sure that the work you did was done 100% correctly. What caps did you use on the speaker?
 
Check the amp at final output. Possible voltage from possible wrong polarity or whatever???
Any volts should be minimal.
 
waggs098 said:
I would open the speaker up and check to make sure that the work you did was done 100% correctly. What caps did you use on the speaker?
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yes i will have a look at my work. NP Mundorf plain caps, as i wanted stock sound for now. for the 4uf the closest was Mundorf 3.9uf. for the 8uf, Mundorf 8.2uf.
 
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pdm4606 said:
Check the amp at final output. Possible voltage from possible wrong polarity or whatever???
Any volts should be minimal.
Click to expand...
I'm forever a layman. do you mean check the output with a multimeter? What setting do I use? Thank you. As I say, the amp plays the large Advents just fine (incredibly fine, by the way).

EDIT: Looks like 1.25V.
 
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I use the cheapest digital VOM for checking. Just put the VOM leads on each side and see what you get. Black lead goes to negative (common) terminal in each situation.
Voltages should be very low. Maybe as low as 0V +- 5 mv. That is very low. As you have a stereo amp of course both sides should be similar.
If there is any deviation an adjustment should be made. The service manual should tell you what is acceptable. Of course the amp should be warm to warmer after a warm up period.
Possibly 30 minutes. Selector set to a non signal input. Volume(level) should be at zero. What you're checking is for a very low voltage at the terminals.
If any voltage outside of the accepted voltage it may be heating up your speaker voice coil or fuse blowing it. If there is a voltage present that is too high, do not use your speakers until the problem is fixed. Maybe ask someone you know that knows how to read very low voltages on a digital meter. It never hurts to ask. But it sure hurts if a voice coil is blown.
 
This is really baffling. The receiver will even play the 4 ohm Advents I have. The receiver blows a fuse playing only this Utah 3-way 36 watt system, which measures 7.6 ohms.
 
Grid said:
This is really baffling. The receiver will even play the 4 ohm Advents I have. The receiver blows a fuse playing only this Utah 3-way 36 watt system, which measures 7.6 ohms.
Click to expand...

Does the speaker do the same thing with other equipment or just the Advent?
 
stereoguy70 said:
Does the speaker do the same thing with other equipment or just the Advent?
Click to expand...
Just the Advent. In fact, I've had it hooked up to my Sansui AU-7900, with four times the watts as the Advent. No problems. I had it hooked up to a Lafayette LR-200 receiver which has a little more watts than the Advent receiver. No problems. And I've had the small 4 ohm and old large Advent speakers hooked up to the Advent receiver. No problems.

I'm getting nearly 8 ohm measurement from this speaker. Yet the Advent receiver fuse blows, but it does not blow with the 4 ohm small Advent speakers connected to it.
 
Resolution? I see this is a couple years old, but if the problem remains unsolved, would like to ask: Does the fuse popping phenomena happen on either Advent 300 channel, or just one? And what kind of music are you playing when the fuse blows, i.e. is there a lot of high frequency content? The resistance of the Utah speaker you measure with the DMM may be very different than the impedance of the speaker across the frequency spectrum. Hope this is resolved, though, and my questions moot.
 
arcsound, the OP hasn't been here in the last 10 months.
We might never know the outcome.
Now watch him post 5 minutes from now...:)
 
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